Hydrodechlorination of chlorofluorocarbons CF3-CFCl2 and CF3-CCl3 over Pd/carbon and Pd black catalysts

The reaction of hydrodechlorination for the chlorofluorocarbons (CFCs) CF3-CFCl2 and CF3-CCl3 was studied over Pd supported on carbon and Pd black catalysts. The rates and selectivity were similar on all samples although Pd black samples had a higher selectivity for the more hydrogenated products. The difference in selectivity and rate for Pd black, is attributed to the presence of an impurity on the surface. The reaction orders are about first order in CFC, half-order in H-2, and inverse first-order in HCl. These results indicate that the irreversible adsorption of CFC is the rate-determining step and that Hz and HCl are equilibrated with hydrogen and chlorine on the surface. Experiments with D-2 On CF3-CFHCl confirm that the adsorption step is irreversible. (C) 2000 Elsevier Science B.V. All rights reserved.